<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>伪元素</title>
    <style>
        p::after{content: '（备注 ）'; color: red;}
        p::before{content:"*" ;}
    </style>
</head>
<body>
    <p>这是一段文字</p>
    <p>我是第一</p>
    <p>我是第二</p>
    <p>我是第三</p>
    <p>我是第四</p>
</body>
</html>